by 1912, American English, first attested in baseball slang; as a type of music, attested from 1913. Probably ultimately from Creole patois jass "strenuous activity," especially "sexual intercourse" but also used of Congo dances, from jasm (1860) "energy, drive," of African origin (compare Mandingo jasi, Temne yas), also the source of slang jism.

If the truth were known about the origin of the word 'Jazz' it would never be mentioned in polite society. ["Étude," Sept. 1924]